FIG. 1 illustrates a circuitry of a conventional LCD. The conventional LCD includes a group of source drivers 56, a group of gate drivers 54, a LCD panel 58 and a timing controller 52. As shown in FIG. 1, a video processing system 50 transmits RGB data and control signals including a clock signal, a horizontal synchronizing signal and a vertical synchronizing signal to a timing controller 52. The timing controller 52 rearranges and transfers the RGB data, and outputs essential control signals to the source driver 56.
An RSDS (reduced swing differential signaling) interface circuit or TTL (single edge of transistor logic) interface circuit is typically used between the timing controller 52 and the group of source drivers 56. In the RSDS or TTL interface, each value of the pixel of red, green or blue is represented by 6 bits, which necessitates 18 wire lines for RGB data transmission. With the demands of higher color resolution and image quality, the number of bits of the pixel value should be increased, for example, to 8 or 10. However, increasing the bits of the pixel value will necessitates more wire lines and therefore result in a larger power consumption, more serious EMI (electromagnetic interference) effect and higher fabrication cost.